The present work aimed to study the efficiency of nanofiltration (NF) and reverse osmosis (RO) process for water recovery from electroplating wastewater and study the factors affecting the performance of two membrane processes. Nanofiltration and reverse osmosis membranes are made from polyamide as spiral wound module. The inorganic materials ZnCl2, CuCl2.2H2O, NiCl2.6H2O and CrCl3.6H2O were used as feed solutions. The operating parameters studied were: operating time, feed concentrations for heavy metal ions, operating pressure, feed flow rate, feed temperature and feed pH. The experimental results showed, the permeate concentration increased and water flux decreased with increase in time from 0 to 70 min. The permeate concentrations increased and flux decreased with increase in feed concentrations from 10 to 300 mg/l. Raising of pressure from 1 to 4 bar, permeate concentration decreased for RO, for NF decreased and then increased at high pressure and increase the flux. The rises of flow rate from 20 to 50 l/h decreased permeate concentration and the flux increase. The rises of temperature from 26 to 40 °C, increased permeate concentration and increased the flux. The rise in pH from 4 to 7, decreased the flux as the pH goes from acidic side towards alkaline. The polyamide nanofiltration membrane had allowed permeation of chromium and copper ions to lower than permissible limits. Nanofiltration membrane had allowed permeation of nickel and zinc ions at low concentration of these ions. The polyamide RO membrane gave a high efficiency for removal of chromium, copper, nickel and zinc and it had allowed permeation of these ions to the lower than permissible limits. The rejection at first three minutes when the feed concentration approximately was constant for chromium in NF and RO, was 99.7% and 99.93%, for copper was 98.43% and 99.33%, for zinc was 97.96% and 99.49%, and for nickel was 97.18% and 99.49% respectively. The maximum recovery for chromium in NF and RO was 71.75% and 48.5%, for copper was 75.62% and 50.68%, for zinc was 80.87% and 54.56%, for nickel was 60.06% and 46.18% respectively. For a mixture of synthetic electroplating wastewater, nanofiltration and reverse osmosis membranes have a high rejection percentage for heavy metal ions. It was obtained pure water and concentrations of less than allowable limits for heavy metals in the case of the mixture.
Background: The aim of this study was to evaluate the shear bond strength (SBS) and adhesive remnant index (ARI) of different orthodontic adhesive systems after exposure to aging media (water storage and acid challenge). Materials and methods: Eighty human upper premolar teeth were extracted for orthodontic purposes and randomly divided into two groups (40 teeth each): the first group in which the bonded teeth were stored in distilled water for 30 days at 37°C, and the second group in which the bonded teeth were subjected to acid challenge. Each group was further subdivided into four subgroups (10 teeth each) according to the type of adhesive system that would be bonded to metal brackets: either non-fluoride releasing adhesive (NFRA),
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The concept of TQM is based on one of the concepts that combine administrative and innovative methods. The aim of the research is to demonstrate the dimensions of TQM in enhancing the satisfaction of the taxpayers through a survey of a sample of officials in the General Authority for Taxation and 50 officials. In the collection of data and information, and the results were analyzed using the SPSS program to find the most important compounds and factors in he method of analysis.
The research problem was represented by the non-application of the General Authority for Taxation to the entrances and modern practices in the administrative work. The results of some of the complications that accompany the tax accounting process, which af
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الضاد والظاء موطن تفرد العربية وفخرها ، الفت فيهما العشرات والعشرات من المصنفات الثرّة لكثرة ذرائع تلابسهما والخلط بينهما ، فهما متشابهان في هيكل البناء ، وإخراجهما متداخل على اللسان ، وألفاظهما متناظرة برحابة في الإملاء ، فضلاعن اشكالهما إلى حدّ الآن ، مما حثني على التفكير في وسائل تسهل المطروح وتمد جسراً بين أجزائه عسى أن تدنو قطافه في دفع الشبهة ومواراتها ، فتحصلت لي امور ادرتها بكلمتين مف
... Show MoreThe human stomach is home to the Gram-negative bacterium Helicobacter pylori, which has been connected to several gastrointestinal disorders. There may be a link between H. pylori infection and the start of autoimmune disorders, according to recent research. This review examines the intricate connections between persistent H. pylori infection, immune system dysregulation, and their possible role in initiating autoimmune disorders. The study begins with a summary of H. pylori infection and its prevalence worldwide, emphasizing the mounting data that connects this bacterium to autoimmune disorders. Then, using experimental data from animal models and epidemiological research as support, it undertakes a thorough review of autoimmune di
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Foreign direct investment is considered one of important bases to blind economy for many. Countries as if the main stage for developing national economy ,so for this ,many of countries give great prominence to the role of drivel foreign investment due to its importance as one of economic growth pillars in the developing countries. They offer a support for modern technology, organizational and managerial skills.
Dneto the importance of direct foreign investment on the economic growth, today, we discover that Iraq in need to rebnlid the in frastructuve and renew what has been destroyed during was in many production and export institutions . as wel
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The aim of the research is to explain the nature of the relationship between the dimensions of the strategic recovery of the service represented by (compensation, speed of response, apology, initiative (defining the problem) and the strategic goals of the company represented in (profitability, growth, community service, employee satisfaction) in the National Insurance Company, it has been approved The questionnaire as a tool to collect data and information from the sample of (58) who are in (department manager, M. department director, division official, unit official) and the statistical program (spss) was used in calculating (arithmetic mean, standard deviation, coefficient of variation, coefficient of Correlation, t-test, varia
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Being the meeting points of the world different languages and out of a scholarly perspective, comparative literature represents a cultural leap as well as an artistic and intellectual development or a global literary movement of both prose and poetry. Such homogenous literary structure requires a systematic and coherent study of the literary output of the people different cultures and civilizations. It also represents the theoretical approach of the present study that debates a systematic comparison between Ghassan Kanafani’s All That's Left to You and William Faulkner’s. The Sound and the Fury. Within the perspective of the descriptive analysis approach, the present paper discusses th
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The planning for the formation of administrative policies and guidance through leadership are important things for managing administrative processes and sporting activities. As both contribute in the stability of the administrative conditions, and their development in the sport federations, whether they both were attentive about team and individual Olympic Games. The two researchers observe that, there is a variation in the correct way of application. Particularly in the formulation of administrative policies and leadership describing it as, modern management standards for both team and individual Olympic Games in the Iraqi National Olympic Committee. That led to cause a misconception and lack of clarity for some administrators of those uni
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